As shown in the figure, a rectangular piece of paper AB is folded in half, with the midpoint O of AB as the vertex, the straight angle is divided into five parts, folded along the five folding lines, and then cut along the CD to make it a regular pentagon (a figure formed by the diagonal of a regular pentagon). Then the degree of ∠OCD is equal to C. 126.
∫∠DOC = 180÷5 = 36∠OCD = 36/2 = 18
∴∠ocd= 180-36- 18 = 126